California c-36 plumbing trade test

Hello, I have been a California contractor for 32 years with a c-27 license and then they split the license into about 5 other  categories,  1 was backflows, so I spent  40 hrs in class and another 3000.oo dollars on the testing and testing equipment, I have  had this business for 4 years and now I have to add the c-36 plumbing trade to my license in order to work in most  bay area Cities, so I need to take the trade part of the c-36 plumbing test, anybody that has taken the test in the last 2 years that can help me out on what  is on the test,I purchased a prep school package but it is tough to know what to study, any help would be great,  thanks